Hard disk drives are information storage devices that use thin film magnetic media to store data. Referring to FIG. 1a, a typical hard disk drive 1 in prior art comprises a head stack assembly (HSA) 10 with slider 11 (shown in FIG. 1b) thereon, a magnetic disk 12 mounted on a spindle motor 13 which causes the magnetic disk 12 to spin, and a motor base 14 to enclose the above-mentioned components.
The slider 11 flies over the surface of the magnetic disk 12 at a high velocity to read data from or write data to concentric data tracks on the magnetic disk 12, which is positioned radially by a voice coil 15 embedded (e.g. by epoxy potting or overmolding) in a fantail spacer 16 of the HSA 10. Generally, a voice coil motor (VCM) 16 is used to drive the voice coil 15.
Referring to FIG. 1b, a traditional HSA 10 includes an actuator coil assembly (ACA) 101, a fantail spacer 16 interposed in the ACA 101 via the voice coil 15, at least an HGA 102 connected with the ACA 101, and a controlling circuit 140 for controlling the HGA 102. The ACA 101 has at least one top surface 131 for mounting the HGA 102, and a side surface 132 for mounting the control circuit 140.
As shown in FIG. 1b, the controlling circuit 140 is a flexible printed circuit assembly (FPCA) that includes a printed circuit board assembly (PCBA) 141 for connecting with a preamplifier (not shown) and a flexible printed circuit (FPC) 142 connecting with the PCBA 141. And the FPC 142 electrically connects to the HGA 102, and mounts on the side surface 132 of the ACA 101.
The HGA 102 includes a suspension 190 and a slider 11 supported by the suspension 190, and the suspension 190 includes a flexure 126 having a head 126a and a tail 126b, and the flexure 126 runs from the slider 11 to the tail 126b. The tail 126 is bent for connecting with the FPC 142. The tail 126 has several bonding pads 128 formed thereon. Concretely, the FPC 142 includes several bonding pads 143 formed thereon. The HGA 102 is connected with the FPC 142 by connected the bonding pads 128 with the bonding pads 143 via several solder joints (not shown). Concretely, a solder joint is formed between the bonding pad 128 of the HGA 102 and the bonding pad 143 of the FPC 142 by using a soldering device.
Additionally, the assembly of the disk drive unit 1 further includes solder joints between the slider 11 and the suspension 190, the FPC 142 and the fantail spacer 16, etc.
During the process of forming the solder joints, defects would be generated due to fine positioning difference between the soldering device and the welded surfaces, or laser energy for melting the solder joint is unstable, and so on. For example, the main defects include bad solder joints, short circuit occurred between adjacent solder joints, and burned surfaces on the FPC 142 or the HGA 102. Thus defective HSAs with defects existing in the HGA 102 and the solder joints are often detected in a subsequent Quasi Static Test process. Therefore, it is necessary to disconnect the defective solder joints between the HGA 102 and the FPC 142 to remove the defective HGA 102 and reuse the other components.
FIG. 2 shows a conventional apparatus for repairing defective solder joints. As shown, the apparatus 200 functions as a repairing device and a soldering device. Concretely, the apparatus 200 includes a laser device 210 including a laser generator 211 and a lens 212 for melting solder ball or solder joint, a device 220 for supplying or collection solder material, a handling device 230 for carrying the process, and a pressure connection 240 for connecting a gas supplying device (not shown) or a pumping device (not shown). When used for a repairing device, the solder joints 251 will be melted by laser beams emitted by the laser device 210 firstly, and then pumped by the pumping device connected with the handled device 230, and finally be connected into the device 220.
As the lens 212 is connected with the top of the handling device 230 directly, that is the top of the handling device 230 is closed by the lens 212, on one hand, it's hard to adjust optical axis of the laser device 210 and the handling device 230; on the other hand, a mass of remains of the solder material will be gathered on the lens 212, which may reduce the stability of the laser energy and reduce its efficiency. Furthermore, due to only one pressure connection 240 is connected with the handling device 230, thus the suction force of the pumping device is not sufficient, which may cause remains of the solder material to block on the outlet of the handling device 230. Thus it's necessary to clean the handling device 230 frequently for ensuring its normal working. However, due to the structure of the handling device 230 is unitary, that is, the outlet and the handling device 230 are integrative, thus it's quite inconvenient to clean or change the handling device 230, which may spend a lot of time and workload.
Therefore, there is a need for an improved apparatus for disconnecting solder joints between two welded surfaces in a disk drive unit to overcome the drawbacks mentioned above.